锂离子电池SnSb/C复合负极材料的热碳还原法制备及电化学性能研究

采用高温还原技术,以SnO2,SbO3为原料,分别以葡萄糖、中间相碳微球(MCMB)作为还原剂,制备了两种结构的SnSb/C复合材料,并对比了它们的形貌和电化学性能.采用X射线衍射技术、拉曼技术、扫描电子显微镜技术对材料的结构和形貌进行了表征,并且通过测试恒电流充放电曲线、循环伏安曲线和交流阻抗谱分析了材料的电化学性能.实验结果表明:葡萄糖作为还原剂时,形成以合金颗粒为内核,絮状碳壳均匀包裹的微米球状结构,首次放电比容量为793.379 mA·h·g-1,循环50周后仍维持在449.987 mA·h·g-1;而以MCMB作为还原剂时,形成合金颗粒与MCMB混合共存并部分包覆的结构,首次放电比容量为1164.938 mA·h·g-1,50周后的比容量仅有290.807 mA·h·g-1.

Lithium intercalation properties of SnSb/C composite in carbonthermal reduction as the anode material for lithium ion battery

The SnSb/C composite material is prepared by using the carbonthermal reduction to deal with the mixture of SnO₂ and SbO₃, respectively with different carbon reductant-glucose and mesocarbon microbead (MCMB). The morphologies and electrochemical properties of two kinds of structures of SnSb/C composite are compared. To characterize the phase and morphology of the composite material, X-ray diffraction, Raman spectra and scanning electron microscope are used. The current charge and discharge, cyclic voltammograms and AC impedancetests are also used to test the electrochemical performance of SnSb/C. The experimental results show that a kind of core-shell structure, of which the alloy particle serves as the core and the pyrolytic carbon as the outside shell, is formed when the glucose is used as the reducing agent. The first discharge specific capacity is 793.379 mA·h/g and it is still kept at 449.987 mA·h/g after 50 cycles. However, when the MCMB is used as the reducing agent, there are only a few of alloy particles attaching to the surface of MCMB, and it is not a kind of core-shell structure but a mixture of alloy particles and MCMB spheres. Its initial discharge specific capacity is 1164.938 mA·h/g, and after 50 cycles it is only 290.807 mA·h/g.
Keywords： SnSb/C carbonthermal reduction lithium ion battery mesocarbon microbeads